iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag

Allow the creation of privileged mode mappings, for stage 1 only.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

drivers/iommu/io-pgtable-arm.c

@@ -350,11 +350,14 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
 
 	if (data->iop.fmt == ARM_64_LPAE_S1 ||
 	    data->iop.fmt == ARM_32_LPAE_S1) {
-		pte = ARM_LPAE_PTE_AP_UNPRIV | ARM_LPAE_PTE_nG;
+		pte = ARM_LPAE_PTE_nG;
 
 		if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
 			pte |= ARM_LPAE_PTE_AP_RDONLY;
 
+		if (!(prot & IOMMU_PRIV))
+			pte |= ARM_LPAE_PTE_AP_UNPRIV;
+
 		if (prot & IOMMU_MMIO)
 			pte |= (ARM_LPAE_MAIR_ATTR_IDX_DEV
 				<< ARM_LPAE_PTE_ATTRINDX_SHIFT);